package com.alan.validate.util;

import java.util.HashMap;

public class IDCardValid {

	final int[] wi = { 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, 1 };
	// verify digit
	final int[] vi = { 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2 };
	private int[] ai = new int[18];
	private static String[] _areaCode = { "11", "12", "13", "14", "15", "21", "22", "23", "31", "32", "33", "34", "35",
			"36", "37", "41", "42", "43", "44", "45", "46", "50", "51", "52", "53", "54", "61", "62", "63", "64", "65",
			"71", "81", "82", "91" };

	private static HashMap<String, Integer> dateMap;
	private static HashMap<String, String> areaCodeMap;
	static {
		dateMap = new HashMap<String, Integer>();
		dateMap.put("01", 31);
		dateMap.put("02", null);
		dateMap.put("03", 31);
		dateMap.put("04", 30);
		dateMap.put("05", 31);
		dateMap.put("06", 30);
		dateMap.put("07", 31);
		dateMap.put("08", 31);
		dateMap.put("09", 30);
		dateMap.put("10", 31);
		dateMap.put("11", 30);
		dateMap.put("12", 31);
		areaCodeMap = new HashMap<String, String>();
		for (String code : _areaCode) {
			areaCodeMap.put(code, null);
		}
	}

	// 验证身份证位数,15位和18位身份证
	public boolean verifyLength(String code) {
		int length = code.length();
		if (length == 15 || length == 18) {
			return true;
		} else {
			return false;
		}
	}

	// 判断地区码
	private boolean verifyAreaCode(String code) {
		String areaCode = code.substring(0, 2);
		if (areaCodeMap.containsKey(areaCode)) {
			return true;
		} else {
			return false;
		}
	}

	// 判断月份和日期
	private boolean verifyBirthdayCode(String code) {
		// 验证月份
		String month = code.substring(10, 12);
		boolean isEighteenCode = (18 == code.length());
		if (!dateMap.containsKey(month)) {
			return false;
		}
		// 验证日期
		String dayCode = code.substring(12, 14);
		Integer day = dateMap.get(month);
		String yearCode = code.substring(6, 10);
		Integer year = Integer.valueOf(yearCode);

		// 非2月的情况
		if (day != null) {
			if (Integer.valueOf(dayCode) > day || Integer.valueOf(dayCode) < 1) {
				return false;
			}
		}
		// 2月的情况
		else {
			// 闰月的情况
			if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
				if (Integer.valueOf(dayCode) > 29 || Integer.valueOf(dayCode) < 1) {
					return false;
				}
			}
			// 非闰月的情况
			else {
				if (Integer.valueOf(dayCode) > 28 || Integer.valueOf(dayCode) < 1) {
					return false;
				}
			}
		}
		return true;
	}

	// 验证身份除了最后位其他的是否包含字母
	private boolean containsAllNumber(String code) {
		String str = "";
		if (code.length() == 15) {
			str = code.substring(0, 15);
		} else if (code.length() == 18) {
			str = code.substring(0, 17);
		}
		char[] ch = str.toCharArray();
		for (int i = 0; i < ch.length; i++) {
			if (!(ch[i] >= '0' && ch[i] <= '9')) {
				return false;
			}
		}
		return true;
	}

	// 验证18位校验码,校验码采用ISO 7064：1983，MOD 11-2 校验码系统
	private boolean verifyMOD(String code) {
		String verify = code.substring(17, 18);
		if ("x".equals(verify)) {
			code = code.replaceAll("x", "X");
			verify = "X";
		}
		String verifyIndex = getVerify(code);
		if (verify.equals(verifyIndex)) {
			return true;
		}
		return false;
	}

	// 获得校验位
	private String getVerify(String eightcardid) {
		int remaining = 0;
		if (eightcardid.length() == 18) {
			eightcardid = eightcardid.substring(0, 17);
		}
		if (eightcardid.length() == 17) {
			int sum = 0;
			for (int i = 0; i < 17; i++) {
				String k = eightcardid.substring(i, i + 1);
				ai[i] = Integer.parseInt(k);
			}
			for (int i = 0; i < 17; i++) {
				sum = sum + wi[i] * ai[i];
			}
			remaining = sum % 11;
		}
		return remaining == 2 ? "X" : String.valueOf(vi[remaining]);
	}

	// 15位转18位身份证
	private String uptoeighteen(String fifteencardid) {
		String eightcardid = fifteencardid.substring(0, 6);
		eightcardid = eightcardid + "19";
		eightcardid = eightcardid + fifteencardid.substring(6, 15);
		eightcardid = eightcardid + getVerify(eightcardid);
		return eightcardid;
	}

	/**
	 * 验证身份证
	 * 
	 * @param idcard
	 * @return
	 */
	public boolean verify(String idcard) {
		// 验证身份证位数,15位和18位身份证
		if (!verifyLength(idcard)) {
			return false;
		}
		// 验证身份除了最后位其他的是否包含字母
		if (!containsAllNumber(idcard)) {
			return false;
		}
		// 如果是15位的就转成18位的身份证
		String eifhteencard = "";
		if (idcard.length() == 15) {
			eifhteencard = uptoeighteen(idcard);
		} else {
			eifhteencard = idcard;
		}
		// 验证身份证的地区码
		if (!verifyAreaCode(eifhteencard)) {
			return false;
		}
		// 判断月份和日期
		if (!verifyBirthdayCode(eifhteencard)) {
			return false;
		}
		// 验证18位校验码,校验码采用ISO 7064：1983，MOD 11-2 校验码系统
		if (!verifyMOD(eifhteencard)) {
			return false;
		}
		return true;
	}

}
